Cafe still exists but the fines are zero currently as the EPA is bringing a new proposal to automakers. Its likely a rollback to 2020 standards with 1% year over year improvements.
Endangerment is going to be stuck in the courts for a while.
I don't see anyway of getting a super majority. You have to get 60 votes in the Senate. Even if you get all 53 Republicans, you are still 7 votes short. Just not going to happen.
Emissions standards and CAFE are likely not going away. They maybe relaxed some to allow more v8s, change some of the derate max speeds, dial back future Emissions standards like LEV4 and Tier 4 but there won't be any extreme changes.